CONTROLLING SEAL SYSTEMS IN ROTARY REGENERATIVE AIR PRE-HEATERS

摘要

Control of the seal (13,25) of a rotary regenerative air preheater (12) is provided by a plurality of inductance sensors (S1-S8, S11-13) arranged around the path of travel of seal parts (13,25) borne by the rotating part (14,20) of the preheater (12). When these are sealing frames (13) borne on hoods (14) of a stationary matrix (11) type preheater (12) drive means such as magnetic actuators (5) are fed power signals through slip rings (4). When they are seal strips (25) on a rotating matrix (20) type, the drive means (D11-D14) are mounted on the sector plates (23,24) of the stationary body (21,22). A control circuit compares the signals received sequentially from the sensors (S1-S8, S11-S13) and drives appropriate one or ones of the drive means (5, D11-D14) to bring the sealing means (13,25) to a predetermined axial relationship, or to hold them there. The sensors(15) may be paired with comparison sensors (16) in the same environment whereby to reduce errors due to changes in temperature etc.